This invention relates to a spine for flexible hoses which can be inserted inside a hose to provide support when the hose is bent, thereby preventing kinking.
In aquariums there is a need to maintain a certain oxygen content in the water so that fish can survive. This is usually accomplished by means of an air pump to which a flexible air hose has been attached. The air hose is bent around the edge of the aquarium and is inserted into the water. Flexbile hoses are susceptible to kinking when bent over a tight radius. Such a kink in an air hose for an aquarium could prove fatal for the fish, since it would prevent the passage of sufficient air into the water.
The bending of tubing frequently causes a problem regardless of the type of material used for the tubing. The problem is one of collapse when the pipe or tubing is bent. Numerous devices have been developed to help prevent such a collapse; for example in U.S. Pat. No. 2,041,428 (Niles, 1934), a means of reinforcing tubing to prevent collapse during a bending operation is disclosed. The means described comprises a spring or tension member suitably positioned and mounted in the tubing where the bend is to be made, such spring or tension member being pinned or attached thereto and retained therein to additionally strengthen the tubing. In U.S. Pat. No. 1,675,574 (Mykins, 1928), a tool for bending lead pipe is disclosed, including a wound spiral coil of suitable diameter which can be reduced by the right hand twisting action of the spring. The spring is inserted into the pipe and serves to aid in the bending thereof.
In U.S. Pat. No. 2,451,717 (Check, 1948), a bending ball arbor is disclosed. Adapted to be positioned interiorly in tubing during the process of bending to insure a relatively smooth and accurate bend in the tube. The device is characterized by lengths securing several balls in related assembly, the lengths being held in position by pins which do not extend exteriorly at the balls, thus obviating the possibility of accidental placement of a pin during the bending operation, and consequently spoilage of the tubing and breakage of the bending apparatus. In U.S. Pat. No. 3,572,083 (Schmitt, 1981), a mandrel for use in effecting small radius seamless bends in rectangular wave guide tubes is disclosed. The mandrel is characterized by a plurality of individual elements secured together by separate shear pins which permit the elements to pivot relative to each other. One face is made at an angle in order to permit bends up to 180.degree. with a minimum radius. These prior art are designed to be used with rigid pipes. One disadvantage is that with the exception of Milligan, the devices are designed to be removed from the pipe after the bending has been effecuated. Another disadvantage is that they are not particularly suitable for use with flexible hoses such as air hoses for aquariums.